What is NST?
NST (Non-stress test) is one of the late pregnancy tests performed to measure uterine contractions and fetal heart rate of the baby. It allows the health status of your baby to be determined.
What else is there: Everything You Wonder About Pregnancy Tests!
How to take NST?
During the NST test, you can monitor the fetal movements with a probe that measures the heart rate of your baby. and a monitor that records uterine contractions is attached. In the meantime, your doctor gives you a bar with a button on it. During the test, it asks you to press this button when your baby moves. Changes in the baby’s heartbeat pattern are observed for 20-30 minutes. These changes occur depending on the baby’s movement. The paper on which the measurements are printed graphically is called the NST tracing. If your baby does not move as a result of NST, it does not mean that there is a problem, it may also be sleeping. Non-reactive testing may indicate that your baby is not getting enough oxygen due to placenta or umbilical cord problems.
Why is NST done?
In addition to a decrease in baby’s movement, NST may also need to be done. These are:
Diabetes, Kidney or heart disease, High blood pressure, Having a stillbirth in the past, Overdose (not giving birth on the given date for birth), Twin baby, Multiple pregnancy.
In what week to enter NST?
Generally, NST can be done from the 28th week of pregnancy. It can be applied in the 26th week in pregnancies with the possibility of preterm birth. However, in this case, a retest is required after 1 week to examine the normal NST values.
In high-risk pregnancies, after the 32nd week, the doctor may want to measure NST at routine examinations.
What is the accuracy of the NST test?
You can get an NST result as if your baby has no problem. There is a high probability of such mistakes in the NST test. However, the margin of error in the results reporting that the baby is healthy is usually low.
The path to information about the health of the baby goes through him: What is Ultrasound, How It Works, What are the Types?
How to interpret the NST?
In the NST graph, the blood flow to the baby In order to be able to say that it is sufficient, the increases in heart rate should be seen twice for at least 15 seconds during the 20-minute examination. If certain criteria are met, reactive NST can be mentioned.
The baby is suspected to be asleep if no movement is observed in the NST device for 20 minutes. In this case, the baby is either expected to wake up spontaneously or it is woken up by a sound stimulation called acoustic stimulation.
After a while, NST is done again. If reactivity criteria are not observed, non-reactive NST is mentioned.
Healthy Pregnancy Guide-Mayo Clinic Experts